Bijensterfte, oorzaken en gevolgen

Marie-Pierre Chauzat, Anne-Claire Martel, Nicolas Cougoule, Philippe Porta, Julie Lachaize, Sarah Zeggane, Michel Aubert, Patrice Carpentier And Jean-Paul Faucon, Environ. Toxicol. Chem. 30, pre-published online.

Abstract — The frequency of occurrence and relative concentration of 44 pesticides in apicultural (Apis mellifera) matrices collected from five French locations (24 apiaries) were assessed from 2002 to 2005. The number and nature of the pesticides investigated varied with the matrices examined—living honeybees, pollen loads, honey, and beeswax. Pollen loads and beeswax had the highest frequency of pesticide occurrence among the apiary matrices examined in the present study, whereas honey samples had the lowest. The imidacloprid group and the fipronil group were detected in sufficient amounts in all matrices to allow statistical comparisons. Some seasonal variation was shown when residues were identified in pollen loads.Given the results (highest frequency of presence) and practical aspects (easy to collect; matrix with no turnover, unlike with bees that are naturally renewed), pollen loads were the best matrix for assessing the presence of pesticide residues in the environment in our given conditions.

Interesting results include:
"The most frequent residues in pollen loads were imidacloprid (in 40.5% of samples), 6-chloronicotinic acid (33.0%), and carbaryl (13.5%)."
and
"The most frequent residues in honey were imidacloprid (in 21.8% of samples) and 6-chloronicotinic acid (17.6%)."

6-chloronicotinic acid is a metabolite of imidacloprid.

Source:
Environmental Toxicology and Chemistry
http://dx.doi.org/10.1002/etc.361